1. Field of the Invention
The present invention relates to a method of cleaning and disinfecting contact lenses which uses a ultrasonic speaker to produce ultrasonic waves for removing dirt from contact lenses, a heating rod to produce heat for sterilizing the contact lens serving solution medium.
2. Description of the Prior Art
Contact lenses have been widely accepted in recent years for the advantage of high convenience, and for some medical considerations for example, highly correcting effect on the deviation of the power of vision and slowing down the deterioration of the power of vision. However, contact lenses must be used subject to a critical hygienic rule, which may affect one's daily life. Before after wearing, contact lenses must be well cleaned and disinfected. When not in use, contact lenses must be well maintained so that the service life of contact lenses can be prolonged. Serving contact lenses is not an easy job. When contact lenses are in use, pollutant for example secretion in tears, dust in air, dirty substance on the skin of the hand or face, etc. may be accumulated on contact lenses, causing the eyes to be stimulated. In order to effectively remove pollutant from contact lenses and to disinfect bacteria, contact lenses are preferably cleaned and disinfected daily. A complete contact lens serving process includes the procedures of cleaning, disinfecting, and storing. Different methods and apparatus may be employed to achieve a complete contact lens serving process.
Conventionally, the cleaning of contact lenses is achieved by rubbing contact lenses with fingers in a cleaning solution. When rubbing a contact lens with fingers, the surface of the contact lens tends to he damaged. This cleaning method cannot only remove grease from the surface of the contact lens, however it cannot remove dirt and bacteria from the capillary tubes of the contact lens. Rubbing a contact lens witch fingers tend to cause the capillary tubes of the contact lens to be blocked up. When the capillary tubes of a contact lens are blocked up, the contact lens become turbid, and white spots may occur in the surface of the contact lens to reduce its air permeability and water absorbing ability.
There are mechanical apparatus controlled to produce a rotary or reciprocating motion, causing the cleaning solution to be stirred up to remove dirt from contact lenses, and apparatus controlled to generate ultrasonic waves, causing a cavitation to be produced to remove dirt from contact lenses. Chemical solutions may be used to dissolve deposits, causing it to leave from contact lenses. Chinese patent no. 75202938 discloses an automatic lens cleaner which comprises a motor a spinning lens holder turned by the motor in a solution trough. When in use the contact lenses must be washed in the cleaning solution in the solution trough through an oxidation or reduction action for at least 30 minutes. Therefore, the user must spend a lot of time in cleaning the contact lenses daily. Furthermore, if the contact lenses are not properly mounted in the spinning lens holder, they tend to be damaged during the spinning of the spinning lens holder.
When a ultrasonic cleaning apparatus is used, ultrasonic waves are transmitted to the cleaning solution to produce a cavitation in it, causing the cleaning solution to produce micro-jets for removing dirt from the contact lenses. This cleaning apparatus is effective and efficient, therefore it is widely accepted by ophthalmologists and professional organizations. However, this apparatus is heavy and expensive, not suitable for personal use.
Using a chemical solution to clean contact lenses has limitations. In order to protect the physical properties of contact lenses, the concentration of the chemical solution must be strictly limited. When cleaning, contact lenses must be dipped in the chemical solution for a long length of time for example from 2 to 12 hours. It is low efficient to spend such a long length of time daily in cleaning contact lenses. Furthermore, regular chemical solutions cannot effectively remove greasy substance or organic matter. In order to effectively clean contact lenses, several chemical solution may be used, thereby causing the cleaning cost unable to be reduced. When cleaning, chemical agent may pass to the inside of the capillary tubes. If the capillary tubes are not well washed, deposited chemical agent may hurt the user's eyes or cause the user's eyes to have an allergy.
When contact lenses are cleaned, a disinfecting procedure must be followed. The disinfecting procedure is to prevent after-effect resulted from enzymatic degradation. There are two methods adapted for achieving the disinfecting procedure, namely, the physical disinfecting method and the chemical disinfecting method. The physical disinfecting method is to sterilize contact lenses by heat or ultraviolet rays. The chemical disinfecting method is to dip contact lenses in a sterilizing solution, permitting organic matter to be killed in the sterilizing solution. Conventional apparatus for sterilizing contact lenses by heat are commonly designed for professional use only. These apparatus have numeral drawbacks as follows: (1) if contact lenses are heated before cleaning or when not well cleaned, protein in tears will be solidified and fixedly secured to the surface of the contact lenses, causing the color of the contact lenses to be changed and the transparency thereof to be reduced; (2) the service life of contact lenses will he shortened if the heating temperature is not well controlled; (3) a serving container means shall be separately used for carrying contact lenses when going outdoors; and (4) a chemical reaction tends to occur during the heating of the contact lenses if chemical solution is not well cleaned, thereby causing the material property of the contact lenses to be affected.
Using ultraviolet rays to sterilize contact lenses cannot eliminate the aforesaid drawbacks. When contact lenses are held in place, there are dead angles around the contact lenses in which ultraviolet rays cannot reach. Therefore, ultraviolet rays cannot effectively sterilize contact lenses. Furthermore, this sterilizing method takes much time.
Because conventional sterilizing apparatus for sterilizing contact lenses by heat or ultraviolet rays are designed for professional use only, most contact lens users use chemical solutions to sterilize contact lenses. However, using chemical sterilizing solutions to sterilize contact lenses wastes much time for example more than 4 hours. These chemical sterilizing solutions commonly contain substance molecules such as chlorohexidine, thimerosal, sorbic acid, hydrogen peroxide, etc. If these molecules are not completely neutralized or removed after the sterilizing procedure, they will injure the cells of the eyes. Because the size of these molecules is tiny and smaller than the inner diameter of the capillary tubes of the contact lenses, they tend to pass to the inside of the capillary tubes, causing the contact lenses to change color, and causing the user to have an allergic reaction when wearing the contact lenses. Furthermore, the expense of the chemical sterilizing solution is another burden to the user.
The last procedure of serving contact lenses is the storing of contact lenses. 0.9% NaCl is commonly used for holding contact lenses in an enclosed container to prevent a contamination when carrying.
As indicated, a variety of apparatus have been disclosed for cleaning and sterilizing contact lenses, and have appeared on the market. However, they still have drawbacks, and cannot fully satisfy individual needs.